Conventionally, diesel particulate filters having oxidation catalyst and filters have been known. Patent Literature 1 discloses an example of an exhaust gas purifying apparatus including such a diesel particulate filter.
The exhaust gas purifying apparatus of Patent Literature 1 carries out post-injection in order to increase temperature of exhaust gas in regeneration of the filter. When the post-injection is performed, fuel is supplied into an exhaust path and oxidation catalyst brings about combustion of the fuel. Then the temperature of the exhaust gas is increased upstream of the filter and the filter is heated by the exhaust gas with the increased temperature. As a result, the filter is regenerated by combustion of particulate matter trapped by the filter. In the exhaust gas purifying apparatus of Patent Literature 1, post-injection quantity is corrected so that temperature of the filter reaches a target temperature. That is, the post-injection quantity is controlled by feedback control in order that the temperature of the filter is increased to and kept at the target temperature.